Fixed a bug in the IT mask printing where T means the cond bit in the mask

Fixed a bug in the IT mask printing where T means the cond bit in the mask
matches that of Firstcond[0] and E means otherwise.  The Firstcond[0] is also
tagged in the Mask to facilitate Asm printing.  The disassembler also depends
on this arrangement.  This is similar to what's described in A2.5.2 ITSTATE.

Ran:

utils/lit/lit.py test/CodeGen/ARM test/CodeGen/Thumb test/CodeGen/Thumb2

successfully.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98775 91177308-0d34-0410-b5e6-96231b3b80d8